US Patent 8477691 Routing VoIP calls to an external network

A system and method for routing calls from a communication system in a VoIP network to an external network. The communication system comprises a plurality of communicating nodes. The communication system is configured to request routing information from a register associated with the external network for routing a communication to a subscriber of the external network, receive routing information from the register, and establish an external connection from the VoIP network for routing the communication to the external network based on the routing information.